The next general election in Malaysia will be held in June 2018.

Malaysian Prime Minister Najib Razak is bracing for the toughest challenge to his government in recent times as Kuala Lumpur witnesses a massive anti-government rally on Saturday. A defiant Najib has said street protests cannot unseat him, referring to the Bersih 5 or 'Yellow Shirt' demonstration seeking his government's ouster.

Najib said the move to remove him from power through mass protests is unconstitutional. He likened the Yellow Shirts movement, which has the solid backing of opposition patriarch Mahathir Mohamad, to the Arab Spring revolution that swept the Middle East earlier this decade.

The embattled prime minister, who has come under wide condemnation over the handling of corruption in the country and the financial scandal at the state investment fund 1 Malaysia Berhad (1MDB), said only popular vote can decide his fate.

"We have seen this happening in many countries. Even the so-called Arab Spring was heralded as an era of change, but instead it caused misery to the people in the countries concerned. .. So the best time to decide is when the time comes,' Najib said in Japan.

The next general election in Malaysia will be held in June 2018.

The street protests are not doing any good to the country, Najib said, adding that it "is not the accepted culture in our country."

Meanwhile, Kuala Lumpur is preparing to deal with clashes on Saturday as outfits supporting Najib and his government under the 'Red Shirts' umbrella have pledged to come out into the streets to confront the Yellow Shirts.

When asked about the law and order scenario on Saturday, Najib said he cannot "guarantee anything." "If one side wants to protest and the side that wants to protect the government is compelled to come out... but I don't want any physical clash," the prime minister said, according to the Malay Mail.

With both the Yellow Shirts and the Red Shirts organising protests in the Dataran Merdeka in the heart of Kuala Lumpur, the city will be under lockdown on Saturday.

The Red Shirts say the Bersih is trying to remove a legally elected government and that the opposition is serving 'foreign agenda'.